1. Field
The present disclosure relates to devices and techniques for reducing the energy consumption of a computer system. More specifically, the present disclosure relates to techniques for reducing the energy consumption in the computer system by monitoring and damping vibrations during a vibration-canceling mode.
2. Related Art
Driven by increasing processor clock speeds, semiconductor integration and computationally intensive applications, thermal loads in computer systems continue to increase. To transport the resulting heat away from critical components, such as processors, many high-end computer systems use increasingly powerful fans. Furthermore, in large-scale computer systems (such as data centers), air-conditioning units are now being mounted as close as possible to servers. For example, large air-conditioning units are now attached to the sides and tops of server racks. The use of larger cooling components in closer proximity to computer systems often exceeds the capabilities of the passive vibration-damping and mechanical-isolation techniques used in existing computer systems.
Concurrently, the scaling of the areal density in hard disk drives (HDDs) is making these devices increasingly sensitive to vibrations. For example, when reading or writing data, a transducer or head in a current HDD may need to follow a track on a spinning disk that is less than 20-nm wide, while maintaining a 7-nm vertical spacing with the disk surface. Even in the absence of external vibrations, it is already difficult to dynamically maintain these small mechanical tolerances. As a consequence, when subjected to external vibrations, track-following by the servo systems in HDDs can be degraded. When this occurs, the input/output (I/O) throughput of the HDDs (and, thus, the performance of the computer system) may be reduced by the resulting read or write retries.
Hence, there is a need for techniques to reduce vibrations in computer systems.